Railway car trap door and folding step construction



July- 26, 193 8. 2 E. F. CHAFFEE 2,124,872 I RAILWAY CAR TRAP DOOR ANDFOLDING STEP CONSTRUCTION Filed Oct. 2. 1936 2 Sheets-Sheet 1 wwfATTORNEYS.

RAILWAY CAR TRARDOORAND FOLDING STEP'CONS'IRUCTION Filed Oct. 2. 1936 2Sheets-Sheet 2 1 VENTOR.

ATTORNEY5.

Patented July 26, 1938 UNITED STATES PATENT OFFICE RAILWAY GAR TRAP DOORAND FOLDING .STEP CONSTRUCTION Application October 2, 1936, Serial No.103,746

6 Claims.

This invention relates to combined trap door and folding steps used investibules of cars of streamlined trains of the general type shown inthe application of Roy T. Axe, Serial Number 15,639, filed April 10,1935 and has for its object a combined trap door and folding stepconstruction in which the trap door unit and step unit are initiallybalanced as near as possible through motion transmitting connectionsbetween them, so that one balances the other when the trap door andsteps reach a partly open position, or one has a certain balancingeffect or slightly over-balancing effect relative to the other, when thetrap door and steps are open, without the use of springs, and meansacting on either the trap door or the step, adjustable to initiallyobtain the predetermined balancing effect in the event the avoirdupoisweights of the trap door and the step do not in themselves accomplishthe predetermined balancing effect, or adjustable to correct anyvariation of the predetermined balancing effect that may develop in thetrap door and step while in use.

More specifically, it has for its object a normally idle spring embodiedin the structure and being inactive in the event the trap door and thesteps balance each other and being adjustable to tension it in eitherdirection to increase or decrease the balancing effect of one relativeto the other, in order to obtain a predetermined balancing effectbetween the. steps and the trap door, that is, the spring may betensioned in one direction to, in effect, lessen the opposing effect ofthe trap door to the step, or, in the opposite direction to increase theopposition of the trap door to the steps.

Other objects will appear throughout the specification.

The invention consists in the novel features and in the combinations andconstructions hereinafter set forth and claimed.

In describing this invention, reference is had to the accompanyingdrawings in which like characters designate corresponding parts in allthe views.

Figure 1 is a fragmentary elevation, partly in section, of a carstructure showing in front elevation, the steps when the trap door andthe steps are open.

Figure 2 is an elevation taken at a right angle to Figure 1, or lookingto the left in Figure 1.

Figure 3 is a view similar to Figure 2 showing the trap door and thesteps in closed position.

Figure 4 is an enlarged fragmentary view of the means for adjusting thespring for obtaining a predetermined balancing eifect between the trapdoor and the steps, this being taken on the plane of line 4-4, Figure 2,in which the trap door is open.

I designates a platform structure of the vestibule of a railway car,which is formed with a trap door opening 2. 3, designates the trap door,and 4 a flight of steps mounted to open or unfold into operativeposition, when the trap door is open and to close or fold up into closedposition when the trap door is closed. The trap door 3 is hinged at oneedge to the platform structure at one side of the trap door opening 2,the axis of the hinge extending transversely of the platform of the car,it being mounted upon a hinge pin 5 which extends through a hinge leafor barrel 6 at one margin of the trap door and which is mounted at itsends in brackets I, 8 on the platform structure at one side of the dooropening 2.

The flight of steps 4 is pivotally mounted in the trap door opening onan axis extending lengthwise of the car structure and in a verticalplane at a right angle to the vertical plane of the axis of the trapdoor 3, it being here shown as having a shaft or tube 9 mounted in theside walls IU of the step structure and extending beyond the side wallsforming studs journalled in bearings ll secured to the walls of the steppassage 2. Reinforcing collars l2 are secured to the side walls Inthrough which the tube extends, the collars being also fixed to theshaft 9 so that the shaft and steps rock as a unit. The shaft 9 islocated relatively to the steps, so that the greater part or greaterweight of the steps is to the outward of the axis of the shaft 9, sothat the greater weight of the steps tends to move the steps by gravityto open position.

In the illustrated embodiment of my invention, the flight of stepsincludes three steps and the axis is located just to the rear of theriser of the second step from the bottom and beneath the tread of thetop step of the flight.

The motiontransmitting means between the trap door and the steps is hereshown as a connecting rod 13 which is secured at its opposite ends tothe under side of the trap door and to the flight of steps in rear ofthe shaft 9 or the axis of the steps 4 by joints having a universalaction to compensate for the differential movements of the trap door andthe steps. As shown, the connecting rod I3 is connected to the tread ofthe top step and in the rear of the vertical plane of the axis of theflight of steps. The connecting rod I3 is capable of extending andshortening against spring means to compensate for differential action ofthe trap door 3 and the steps 4 and also to permit continued openingmovement of the door 3 when the steps reach open position and alsocontinued closing movement of the trap door after the folding steps 4reach their closed position. When the steps 4 reach their open position,a stop surface or flange l4 here shown as located at the rear edge ofthe tread of the top step abuts against a flange at [5 on the platformstructure.

When the steps reach their closed position, the outer edge or the outeredge of the tread of the bottom step is in position to meet the trapdoor when the trap door is fully closed. The steps reach folded positionhowever before the trap door is fully closed and due to the angularityand direction of thrust of the 'connecting rod i3, as shown in Figure 3,and of the theoretical lever arm between the shaft 9 and the lower endof the connecting rod l3, the folding steps do not move beyond theirclosed position duringthe final closing movement of the trap door 3.

The connecting rod I3 is constructed to elongate against spring actionduring the opening of the trap door after the folding steps have reachedtheir final open position with the flange I4 engaged with the stopflange 15, so that continued opening movement of the trap door isagainst the action of the spring means in the connecting rod l3. Duringsuch continued movement, the connecting rod moves beyond a dead centerline toself-locking position, that is, beyond a line passing through theaxis of the trap door and the axis of the universal joint between thelower end of the connecting rod and the steps. When the steps havereached their final closed position in advance of the trap door,continued movement of the trap door into closed position causes theconnecting rod I3 to shorten against the action of a compression spring.The trap door is held in its closed position by a latch l6 of any wellknown construction commonly used with the trap doors of railway cars-The operation of the connecting rod I3 is substantially the same as thatshown in the Axe application Serial No. 15,639, although the springmeans in the connecting rod is slightly different from that shown in theAxe application. The connecting rod structure here shown consists of arod which is secured at its lower end to a head or clevis l1 pivoted toone end of a stud l8 journalled in a horizontal or radial bearing I9 ona plate 2| secured in the tread of the top step of the flight of steps4, and which, at its upper end, is slidably or tele scopingly mounted ina head 22 pivoted at 23 to the end of a stud 24 having a base 24swivelly mounted in the trap door. Springs 25, 26 encircle the rod,these springs being located in a barrel 2'! movable as a unit with theupper head 22. The rod has an annular shoulder 28 or spring abutmentwithin the barrel. The spring 25 thrusts against the upper side of saidshoulder 28 and the lower side of the upper head 22 and the spring 26against the lower side of the shoulder 28 and a head or shoulder 29 atthe lower end of the barrel. During the opening of the trap door, thespring 26 compresses, when the folding steps reach and are stopped Intheir extended position, and during closing of the trap door, the upperspring 25 compresses durlne the final closing or th trap door a er thesteps have reached their closed position" The rod telescopes during thelengthening and. shortening of the connecting rod structure inthe upperhead 22.

The general operation, with the exception of the specific springstructure, is practically the same as in the Axe application referredto.

The trap door and the folding steps are so located that the avoirdupoisweight of the steps slightly overbalances the weight of the trap door,so that when the latch i6 is released, the weight of the steps willslightly overbalance the weight of the trap door when closed and causethe trap door to partly open, say six inches, more or less. The portercontinues to open the steps by hand, but the weight of the steps andtrap 7 door being balanced, only sufficient force is nec-- essary tokeep them in 'motion. However, due to changes that might be made inmaterial, and to conditions that may develop during the use of the .trapdoor, the original balance may be" upset and hence, means is providedfor adjusting the balance of the trap door and the steps initially, ifsuch balancing is necessary, and also in order to maintain the balancein case it is upset by friction or lack of friction and other conditionsthat may develop during continued use of the structure. With the stepsand the trap door both made of the same material, as for instance,aluminum or steel, the trap door and the steps are quite likely tobalance properly without the use of adjusting means. However, if forinstance, the steps are of aluminum and the trap door of steel, meansfor initially adjusting the balance is necessary. The balance may beadjusted by adding additional weight to the part that is too light, butpreferably, easily operable adjusting means is provided, this being aspring so located as to be normally idle in case no adjustment isnecessary and to be tensioned in one direction or the other to lightenthe effective weight of the too heavy part or increase the weight of thetoo light part.

In the illustrated embodiment of my invention, the spring is applied tothe trap door at the axis thereof, as the outer end of the trap doorhinge is exposed and readily accessible, and the hinge of the steps isless accessible under the steps.

30 designates a spring, which is a laminated torque spring, of the usualconstruction used in railway car trap doors, it having one end anchoredat 3| to the barrel 6 of the trap door and having its other end securedto a head 32, the head 32 being normally rotatable in the bracket 7 andas a unit with the barrel 6 of the trap door, so that the spring is idleor ineffective. The head 32 is provided with'a'wrenchhold by means ofwhich it can be turned in one direction or the other to tension thespring, and a key 33 is provided for locking it in any one of aplurality of angular or radial positions in the bearing of the bracket1, when the spring is tensioned, the key being applied through any oneof a plurality of holes 34 in the bearing of the bracket 1 to enter anyone of a plurality of holes 35 in the head 32 and located at differentradial angles relatively to each other. The holes are to lock the headin various positions in accordance with the degree to which the springis tensioned. The pin, when not in use, extends through a slot 36(Figure 4) in the bearing of the bracket 1, the slot being long enoughto not obstruct the free rotation of the head 32- dging the opening andclosing movement of the trap door when the spring is not tensioned, thatis, when the. trap door and steps balance without spring tension. InFigure 4, which is an enlarged view taken on line 44, Figure 2, theparts are in their positions assumed, when the trap door and steps areopen. If the trap door should be initially too heavy for the properbalancing of the trap door and the steps, the spring 30 is tensioned insuch direction as to tend to open the trap door. If the trap door shouldbe too light for the proper balancing of the trap door and the steps,the spring is tensioned in the opposite direction to, in effect,increase the weight of the trap door and its tendency to close.

The trap door and the steps may initially balance each other properly,so that when the latch H5 is released, the steps 4 will slightlyoverbalance the trap door and cause the trap door to partly open.However, during the continued use of the structure, under someconditions, additional friction may develop and under other conditions,friction in the hinge or pivot bearings decrease so that it is necessaryto tension the spring in one direction or the other to maintain theslightly overbalancing effect of the steps on the trap door.

Owing to the fact that a predetermined balancing effect is obtained asnearly as possible, by the relative avoirdupois weights of the trap doorand the steps, a spring under slight tension only is necessary to adjustand maintain the predetermined balance, and hence, there is only aremote liability of the spring breaking. In trap door constructions, thesprings, because of the fact that they are under comparatively greattension are liable to break. In combined trap door and stepconstructions relying only on a spring or springs, either in the trapdoor or in the steps or in both, the springs are initially under suchtension that they are liable to break frequently. 7

In order to insure that the flight of steps will be held solidly in openposition andwill not give or vibrate when the passengers are using themand thus give the user a sense of insecurity, adjustable stop means isprovided. This means, as here shown, includes adjustable stop elementson the flange l5, as set screws 4|, extending through the flange I5 andagainst which the flange M on the steps engage, when the steps are inopen position. As here shown, two stop screws 4| are located to engagethe flange l4 near opposite ends thereof or near opposite sides of theflight of steps or the stop screws are spaced apart in a directionwidthwise of the steps. These screws 4| are adjustable differentdistances below the flange l5, so that the flange l4 comes up solidlyagainst both stop screws, when the steps are folded or open. There maybe any number of spaced apart stops or screws, but ordinarily two,located as described, are sufiicient. These adjustable stops constitutean object of the invention, and by the use of these set screws, aconnecting rod may be used without spring means or resiliency permittingit to elongate and shorten, as initially, a connecting rod of the properlength can be used or adjusted to the proper length by threading one ofthe clevises or heads, as the head ll, thereon the right distance forthe installation, and looking it by means of a lock nut in its setposition, or a connecting rod embodying a turn-buckle may be used. Thus,the connecting rod may be adjusted to the proper length for eachinstallation and the. set screws 4| adjusted correspondingly to hold theflight of steps 4 solidly when the trap door is fully open.

By this invention, the trap door and the steps are originally balanced,so that no spring is necessary, but a spring is applied as an emergencyproposition in case the conditions vary during the use of the structure,and also to initially make up for any slight differences in thepredetermined balancing effect that maybe actually present when the trapdoor and steps are initially assembled.

What I claim is:

1. In a trap door and folding step construction for railway cars, thecombination of a platform structure formed with a step passage, a flightof steps pivotally mounted on a horizontal axis to the platformstructure within the passage and below the level of the platformstructure, a trap door hinged to the platform structure at one side ofthe step passage and arranged to cover and uncover the step passage,motion transmitting connections between! the trapdoor and the stepsandoperating to move the steps into operative position, as the trap dooropens, and move the steps into inoperative position, as the trap doorcloses, the flight of steps being mounted on its pivotal axis to move bygravity toward operative position and thereby tend to move the door fromclosed position, and the door and steps being so mounted with respect totheir pivotal axes that the avoirdupois Weights thereof balance throughthe motion transmitting means, when the door assumes a partly openposition, and releasable means for holding the trap door closed.

2'. In a trap door and folding step construction for railway cars, thecombination of a platform structure formed with a step passage, a stepunit pivotally mounted on a horizontal axis to the platform structurewithin the passage and below the level of the platform, a trap door unithinged to the platform structure at one side of the step passage andarranged to cover and uncover the step passage, motion transmittingconnections between the trap door and the step units and operating tomove the step unit into operative position, as the trap door unit opens,and move the step unit into inoperative position as the trap door unitcloses, the step unit being mounted on its pivotal axis to move bygravity toward operative position and thereby tend to move the door unitfrom closed position, and the door and step units being so mounted withrespect to their pivotal axes that the avoirdupois weights thereofbalance through the motion transmitting means, when the door unitassumes a partly open position, releasable means for holding the trapdoor closed, and adjustable means connected to one of said units forvarying the amount of the balancing action of one unit on the other,through said motion transmitting connections.

3. In a trap door and folding step construction for railway cars, thecombination of a platform structure formed with a step passage, 9. stepunit pivotally mounted on a horizontal axis to the platform structurewithin the passage and below the level of the platform, a trap door unithinged to the platform structure at one side of the step passage andarranged to cover and uncover the step passage, motion transmittingconnections between the trap door and the step units and operating tomove the step unit into operative position, as the trap door unit opens,

and move the step unit into inoperative position, as the trap door unitcloses, the step unit being mounted on its pivotal axis to move bygravity toward operative position and thereby tend to move the door unitfrom closed position, and the door and step units being so mounted withrespect to their pivotal axes that the avoirdupois weights thereofbalance through the motion transmitting means, when the door unitassumes a partly open position, releasable means for holding the trapdoor unit closed, and a torsion spring connected to one of said units,an adjustable member to which the spring is connected, the adjustablemember being normally idle, whereby the spring is without tension andbeing operable into various positions to tension the spring differentdegrees in one direction or the other and thereby adjust thecounterbalancing action of one unit relatively to the other.

4. In a trap door and folding step construction for railway cars, thecombination of a platform structure formed with a step passage, a stepunit pivotally mounted on a horizontal axis to the platform structurewithin the passage and below the level of the platform, a trap door unithinged to the platform structure at one side of the step passage andarranged to cover and uncover the step passage, motion transmittingconnections between the trap door and the step units and operating tomove the step unit into operative position as the trap door unit opens,and move the step unit into inoperative position as mounted on itspivotal axis to move by gravity the trap door unit closes, the step unitbeing mounted on its pivotal axis to move by gravity toward operativeposition and thereby tend to move the door unit from closed position,and the door and step units being so mounted with respect to theirpivotal axes that the avoirdupois Weights thereof balance through themotion transmitting means, when the door unit assumes a partly openposition, releasable means for holding the trap door unit closed, and atorque spring arranged coaxially with the hinge of one of said units andanchored to said unit, a head to which the other end of the spring isanchored, and normally capable of free movement about the axis of and insynchronism with the unit to which the spring is anchored, said headbeing operable about the axis of the spring in either direction totension the spring in one direction or the other, and means foranchoring the head from turning movement when the spring is tensioned,all whereby the head is operable to vary the tension of the spring andthe amount of the balancing effect of one unit on the other through themotion transmitting connections.

5. In a trap door and folding step construction for railway cars, thecombination of a platform structure formed with a step passage, a stepunit pivotally mounted on a horizontal axis to the platform structurewithin the passage and below the level of the platform, a trap door unithinged to the platform structure at one side of the step passage andarranged to cover and uncover the step passage, motion transmittingconnections between the trap door and the step units and operating tomove the step unit into operative position as the trap door unit opensand move the step unit into inoperative position as the trap door unitcloses, the step unit being mounted on its pivotal axis to move bygravity toward operative position and thereby tend to move the door unitfrom closed position, and the door and step units being so mounted withrespect to their pivotal axes that the weights thereof balance throughthe motion transmitting means, when the door unit assumes a partly openposition, releasable means for holding the trap door unit closed, and atorsion spring connected to one of said units, an adjustable member towhich the spring is connected, the adjustable member being normallyidle, whereby the spring is without tension and being operable intovarious positions to tension the spring different degrees in onedirection or the other, and thereby adjust the counterbalancing actionof one unit relatively to the other, said motion transmittingconnections including a spring means causing the same to lengthen duringmovement of the door unit when the step unit has reached operativeposition and to shorten during continued closing movement of the doorunit after the step unit has reached inoperative position.

6. In a trap door and folding step construction for railway cars, thecombination of a platform structure formed with a step passage, a stepunit pivotally mounted on a horizontal axis to the platform structurewithin the passage and below the level of the platform, a trap door unithinged to the platform structure at one side of the step passage andarranged to cover and uncover the step passage, motion transmittingconnections between the trap door and the step units and operating tomove the step unit into operative position as the trap door unit opensand move the step unit into inoperative position as the trap door unitcloses, the step unit being mounted on its pivotal axis to move bygravity toward operative position and thereby tend to move the door unitfrom closed position, and the door and step units being so mounted withrespect to their pivotal axes that the weights thereof balance throughthe motion transmitting means, when the door unit assumes a partly openposition, releasable means for holding the trap door unit closed, and atorsion spring connected to one of said units, an adjustable member towhich the spring is connected, the adjustable member being normallyidle, whereby the spring is without tension and being operable intovarious positions to tension the spring different degrees in onedirection or the other, and thereby adjust the counterbalancing actionof one unit relatively to the other, said motion transmittingconnections including a spring means causing the same to lengthen duringcontinued movement of the door unit when the step unit has reachedoperative position and to shorten during continued closing movement ofthe door unit after the step unit has reached inoperative position, andmeans for coacting with the step unit for limiting the opening movementthereof before the door has reached its fully open position, and meansfor limiting the closing movement of the step unit before the door unithas reached its completely closed position.

EDWARD F. CHAFFEE.

Patent No. 2,12h,872.

' to move by gravity; and that the said Le CERTIFICATE OF CORRECTION.

July 26, 1958.

EDWARD F. CHAFFEE.

It is hereby certified that error appears in of the above numberedpatent requi ring correction as follows: Page Lt, first strike out thewords "mounted on itspivotal axis tters Patent should be read with 0rdof the case the printed specific at ion column, line 55, claim h,

this correction therein that the same'may conform to the rec in thePatent Office.

Signed and sealed this 50th day of August, A. D. 1958.

Henry Van Arsdale (Seal) Acting Commissioner of Patents.

